// Copyright 2011 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package main import ( "go/ast" "go/token" ) var stringssplitFix = fix{ "stringssplit", stringssplit, `Restore strings.Split to its original meaning and add strings.SplitN. Bytes too. http://codereview.appspot.com/4661051 `, } func init() { register(stringssplitFix) } func stringssplit(f *ast.File) bool { if !imports(f, "bytes") && !imports(f, "strings") { return false } fixed := false walk(f, func(n interface{}) { call, ok := n.(*ast.CallExpr) // func Split(s, sep string, n int) []string // func SplitAfter(s, sep string, n int) []string if !ok || len(call.Args) != 3 { return } // Is this our function? switch { case isPkgDot(call.Fun, "bytes", "Split"): case isPkgDot(call.Fun, "bytes", "SplitAfter"): case isPkgDot(call.Fun, "strings", "Split"): case isPkgDot(call.Fun, "strings", "SplitAfter"): default: return } sel := call.Fun.(*ast.SelectorExpr) args := call.Args fixed = true // We're committed. // Is the last argument -1? If so, drop the arg. // (Actually we just look for a negative integer literal.) // Otherwise, Split->SplitN and keep the arg. final := args[2] if unary, ok := final.(*ast.UnaryExpr); ok && unary.Op == token.SUB { if lit, ok := unary.X.(*ast.BasicLit); ok { // Is it an integer? If so, it's a negative integer and that's what we're after. if lit.Kind == token.INT { // drop the last arg. call.Args = args[0:2] return } } } // If not, rename and keep the argument list. sel.Sel.Name += "N" }) return fixed }